Aligned PLGA/nHA fiber scaffolds for enhancing osteogenic differentiation of human periodontal ligament stem cells

The aim of this study was to investigate the effects of aligned poly (lactic-co-glycolic acid)/nano-hydroxyapatite (PLGA/nHA) fiber scaffolds with micro-/nanostructures on the osteogenic differentiation potential of human periodontal ligament stem cells (hPDLSCs).

Aligned/random PLGA and PLGA/nHA fiber scaffolds with micro-/nanostructures were created by electrospinning. Comprehensive characterization of the scaffolds with scanning electron microscopy (SEM), X-ray diffraction, Fourier transform infrared spectroscopy, mechanical testing, thermogravimetric analysis and hydrophilicity was performed. In addition, they were observed if they could promote the osteogenic differentiation of hPDLSCs by RT-qPCR, SEM, alkaline phosphatase staining and alizarin red staining. The subcellular distribution of YAP protein between the nucleus and cytoplasm was detected by YAP immunofluorescence staining.

Aligned PLGA/nHA fiber scaffolds had a better mechanical strength, thermal stability, hydrophilicity than random fiber scaffolds. Furthermore, aligned PLGA/nHA scaffolds also promoted cell adhesion, obvious cytoskeletal elongation and enhanced osteogenic differentiation of hPDLSCs was observed by the upregulation of the key genes (OCN, RUNX2, OPN) expression, increased the activity of alkaline phosphatase, and positive for alizarin red. Meanwhile, the a-PLGA/nHA scaffolds showed the strongest nuclear YAP fluorescence intensity.

The synergistic effect of fiber arrangement and nHA can be used to increase the osteogenic differentiation of hPDLSCs and the composite scaffold developed may have translational potential for alveolar bone regeneration.